[foreign-memaccess+abi] Integrated: 8291873: Implement return value normalization in Java

[Jorn Vernee]

On Wed, 14 Sep 2022 17:17:46 GMT, Jorn Vernee <jvernee at openjdk.org> wrote:

> This patch moves value normalization code from the downcall stub (where it was hard coded) to Java, and also adds it for upcall arguments where it was missing.
> 
> ~There is a slight change in behavior with this. The previous hard-coded conversion from a native value to Java `boolean` checked if the least significant byte was non-zero, i.e. `boolean result = value & 0xFF != 0`. While the new conversion only looks at the least significant bit, i.e. `boolean result = value & 0b1 != 0`. I think the new behavior is more correct. It means that the Linker will just do the "dumb" thing when mapping anything to `boolean`, and the native representation is really expected to be like a Java `boolean` i.e. only using the least significant bit. On the other hand I think it means that e.g. jextract will have to map the C `bool` as `byte` and then do a non-zero check to convert to `boolean`.~

This pull request has now been integrated.

Changeset: 3e8ef17b
Author:    Jorn Vernee <jvernee at openjdk.org>
URL:       https://git.openjdk.org/panama-foreign/commit/3e8ef17b89244a7daac63b08a8a25fb0a12c24e9
Stats:     407 lines in 9 files changed: 357 ins; 35 del; 15 mod

8291873: Implement return value normalization in Java

Reviewed-by: mcimadamore

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PR: https://git.openjdk.org/panama-foreign/pull/720